Abstract

Twenty-six species of subterranean amphipods have been described from the Pilbara, Western Australia, based on variation in morphological characters. Many are known only from single bores. The Pilbara is rich in iron ore, and thus, an understanding of species’ diversity and their distribution is necessary both to manage resources and to conserve fauna. A previous allozyme study of nine bores in a single catchment in the Pilbara found low levels of genetic differentiation among individuals, but the diversity was not associated with single bores. The area studied appeared to contain a single widespread species common to all nine bores, in sympatry with a second, rare species, represented by a single specimen. The present study analysed allozymic variation in amphipods from 26 bores in four additional catchments in the Pilbara, to test the generality of these findings. At each site, samples with similar allelic arrays were found in multiple bores, in sympatry with rare divergent genotypes. Geological complexity was associated with increased genetic differentiation over short geographical distances. With few exceptions, each catchment contained a unique suite of species, suggesting that catchments may form hydrological barriers to gene flow, resulting in local speciation events.

Extra keywords: biodiversity, conservation, stygofauna.

References

Barnard
J. L.
Williams
W. D.
1995
The taxonomy of the Amphipods (Crustacea) from Australian fresh waters: part 2.
Records of the Australian Museum
47
161
201

Bradbury
J.H.
2000
Western Australian stygobiont amphipods (Crustacea: Paramelitidae) from the Mt Newman and Millstream regions.
‘Records of the Western Australian Museum Supplement No. 60’
Western Australian MuseumPerth, Australia

Bradbury
J. H.
Williams
W. D.
1997
The amphipod (Crustacea) stygofauna of Australia: Description of new taxa (Melitidae, Neoniphargidae, Paramelitidae), and a synopsis of known species.
Records of the Australian Museum
49
249
341

Swofford
D. L.
Selander
R. B.
1989
‘BIOSYS. A Computer Program for the Analysis of Allelic Variation in Genetics.’
Department of Genetics and Development, University of IllinoisUrbana-Champaign, IL, USA.